Process for feltproofing and shrink-proofing wool and textiles containing wool in alkaline baths and treatment baths therefor



niterl tates tent i iatentedl Jan. 1, 1953 3,671 431 PRUEESS FOR FELTPRQFTN G AND SHRINK- PRGUFENQ W601 AND TEXTILES CUNTAINING WEINBL EN ALKALENE EATHS AND TREATMENT THEREFOR Heinrich Martens and Josef Stadier, both of Ludwigshafen (Rhine), Germany, assignors to Badische Anilinez Soda Fahrik Aktiengeselischaft, Ludwigshafen (Rhine), Germany No Drawing. Filed Sept. 22, 1960, Ser. No. 57,635 Claims priority, application Germany Sept. 26, 1959 3 Qtairns. (Cl. 8-=-128) The present invention relates to a process carried out in alkaline baths, for rendering Wool and wool-containing textiles proof against felting and shrinkage (hereinafter referred to as feltproofing and shrinkproofing) and to treatment baths for carrying out such a process.

it is known that the resistance of wool or wool-containing textiles to shrinkage and felting can be increased by treating the fibrous material with oxidizing agents, such as the sodium salt of para-toluene sulfonic acid chlorimide, gaseous chlorine or chlorine water or hypochlorite. The treatment was gaseous chlorine is usually rejected for practical reasons. In the liquid phase and in acid medium, the chlorine acts too turbulently and irregularly on the wool. One of the consequences is that difficulties are encountered in dyeing the wool. Various remedies have been sought, such as adding the chlorine in small batches, in the form of loose chlorine adducts or by coemploying low molecular weight agents capable of binding chlorine temporarily; it has not been possible however to obviate the disadvantages in this way. All these oxidation processes have the disadvantage that they change the wool chemically in an undesirable way and thereby damage it.

Since wool fibers undergo very little damage in weak alkaline baths, and according to recent investigations may even undergo advantageous changes therein, it has been desirable to find an industrial process which operates in the alkaline range. The oxidizing agents mentioned above have proved unsuitable for this purpose. For example when oxidizing with chlorine in alkaline medium, long treatment periods are required by reason of the slow reaction speed, unless the amount of chlorine is increased to an inconveniently high extent. The advantages of the alkaline treatment bath are thus nullified.

in order to circumvent these ditl'lculties in alkaline treatment, attempts have been made to improve wool by treating it simultaneously or successively with aqueous alkaline solution of alkali permanganates and aqueous alkaline solutions or dispersions of an alkali or alkaline earth hypcchlorite or a nitrogen-chlorine compound, such as nitrogen trichloride, monochlorarnine or para-toluenesulfone chloramide. It is true that in this way it is possible satisfactorily to diminish the tendency of the wool to felt and shrink, but the fibrous material is at the same time considerably contaminated by the precipitated pyrolusite. It is very difficult to remove the pyrolusite completely by an after-treatment.

It is an object of the present invention to provide an improved process by which wool and wool-containing textiles can be feltproofed and shrinkproofed in alkaline baths.

Another object of the invention is to provide alkaline treatment baths for the feltproofing and shrinkproofing of wool and wool-containing textiles which do not contaminate with pyrolusite or other firmly-adherent substances the textile materials treated therewith.

A special object of the invention isto provide wool and wool-containing textiles exhibiting improved fastness to felting and shrinkage without at the same time damaging the material treated.

These objects are achieved in accordance with this 2 invention by treating the fibrous material with dichlorcyanuric acid in alkaline aqueous solution, which may contain an inorganic and/or organic salt and if desired other usual oxidizing agents, and if desired subjecting the fibrous material to a conventional oxidative or reductive dechlorination.

The oxidizing agent dichlorcyanuric acid should in general be present in the treatment bath in an amount corresponding to 2 to 5% of active chlorine with reference to the weight of treated material The baths therefore contain about 2.8 to 7% by weight of dichlorcyanuric acid. Larger amounts of these substances may be present in the baths, but the economy of the process then suffers. The baths may also contain other oxidizing agents usual for textile treatment, such as salts of peroxymonosulfuric acid, peroxydisulfuric acid, peracetic acid and perbenzoic acid. Furthermore inorganic salts such as sodium chloride, sodium bromide, sodium sulfate, calcium chloride, magnesium sulfate and zinc sulfate and/ or organic salts, as for example the alkali and alkaline earth salts of acetic acid and ethylenediaminotetracetic acid, may also be added to the baths. Wetting agents of the kind usual for textile treatment may also be added to the bath to increase the Wettability of the material being treated. In particular the process may be carried out in a bath which is saturated with sodium chloride.

The treatment bath is so adjusted by the addition of alkaline-reacting substances, preferably of buffer substances, such as borax or alkali phosphates, that it has a pH above 7; baths with a pH between 7 and 8.5 are of special advantage.

The process is carried out at room or elevated temperature. It is advantageous to use temperatures of 20 to 40 C. As a rule it is not necessary to work above 70 C. The duration of the treatment is dependent on the temperature. At room temperature, a reaction period of about an hour is usually sufficient. The material thus treated is then rinsed with cold water.

With the new process, a considerably better feltproofing and shrinkproofing effect is obtained than by the known methods without it being necessary to accept any appreciable damage to the fibers.

A further advantage of the process according to this invention is that it does not lead to yellowing, as for example the known treatment with hypochlorite, but rather leads to a noticeable brightening of the wool fiber.

Any later occurrence of yellowing of the fibrous material can be safely prevented by adding a treatment in a reductive or oxidative dechlorination bath. For this purpose the rinsed material is introduced into a bath which contains a reducing agent, for example an alkali bisulfite, an alkali dithionite, a salt of a hydroxyalkane-sulfinic acid or a reaction product of such an acid with ammonia, or an oxidizing agent, as for example hydrogen peroxide. Such baths are generally used for dechlorination. They can be adjusted to be acid, neutral or alkaline depending on the nature of the active substances contained therein.

It is true that it is already known that wool can be made feltproof and shrinkproof with chlorinated cyanuric acids in acid baths. Since, however, chlorinated cyanuric acids in acid medium react with wool more slowly than free chlorine or hypocnlorite, it could not be foreseen that their use in alkaline baths, in which the usual chlorinating agents are insufficiently effective would lead to the desired result.

As compared with the treatment with chlorinated cyanuric acids in acid baths, the new process has the advantage that the improved wool, with the same feltproofing and shrinkproofing efiects, is less attacked and acquires a superior handle. Moreover by reason of the use of alkaline baths, the metal parts of the textile machines and apparatus are less attacked than when using acid treatl (a) Hypochlorite ment baths containing active chlorine which even many alloy steels will withstand for only limited periods.

The following examples will further illustrate this invention but the invention is not restricted to these examples. Unless otherwise stated, the percentages are by weight.

Example 1 3 samples of wool fabric (worsted fabric) are treated at room temperature at a liquor ratio of 30:1 for an hour in a bath (a, b or c) which contains, with reference to the weight of the material, of calcium chloride, 4% of borax, 2% of potassium permanganate and 3.5% of active chlorine in the form of hypochlorite (bath a) and dichlorcyanuric acid (bath b). The pH of the baths is adjusted to 8.5 prior to adding the wool.

After the wool has been removed from the oxidizing bath, it is rinsed for a short time and then treated in a bath which has a pH between 3 and 4 and contains about 10% of bisulfite, at a liquor ratio of :1, and then rinsed again.

A washing test carried out for 3 hours gives the fol1owing values for surface shrinkage:

Percent surface shrinkage (a) Hypochlorite 34.41 (b) Dichlorcyanuric acid 9.2

If 2% of potassium permanganate is further added to the bath containing hypochlorite (bath a), the following value is obtained for the surface shrinkage:

Percent surface shrinkage (a) Hypochlorite 22.7

Example 2 3 W001 samples are treated as described in Example 1 in three baths which contain 10% of sodium chloride, 4% of sodium pyrophosphate and 3.5% of active chlorine in the form of hypochlorite (bath a) and dichlorcyanuric acid (bath b). A washing test carried out for 3 hours gives the following values for the surface shrinkage:

Percent surface shrinkage .2

(l1) Dichlorcyanuric acid 8.8

If the bath a containing sodium hypochlorite has 2% of potassium permanganate added to it, the following value is obtained for the surface shrinkage:

Percent surface shrinkage (a) Hypochlorite 18.3

Example 3 2 samples of wool fabric are treated at a liquor ratio of :1 for an hour at 25 C. in two different baths (a and b) which, calculated on the weight of the fabric, contain 10% of sodium sulfate, 8% of sodium pyrophosphate and 4% of active chlorine in the form of hypochlorite (bath a) and dichlorcyanuric acid (bath b). The pH of the bath is adjusted to 7 prior to adding the wool.

The wool is removed from the oxidizing bath, rinsed for a short time with water, treated for an hour at C. at liquor ratio of 20:1 in a bath which contains 3 grams per liter of sodium dithionite, 0.125 gram per liter of sodium sperm oil alcohol sulfate and 0.125 gram per liter of Glaubers salt, and then rinsed again with water.

A washing test carried out for 3 hours gives the following values for surface shrinkage:

Percent surface shrinkage (a) Hypochlorite 35.64 (b) Dichlorcyanuric acid 8.96

Untreated Wool underwent a 48.17% surface shrinkage in the washing.

4 Example 2 samples of wool fabric are treated at a liquor ratio of 40:1 for an hour at 25 C. in two different baths (a and b) which, calculated on the weight of the fabric, contain 10% of sodium sulfate, 8% of sodium pyrophosphate and 4% of active chlorine in the form of hypochlorite (bath a) and dichlorcyanuric acid (bath b). The pH of the bath is adjusted to 7.5 prior to adding the wool.

The wool is removed from the oxidizing bath, rinsed for a short time with water, treated for an hour at 50 C. at a liquor ratio of 20:1 in a bath which contains 3 grams per liter of sodium dithionite, 0.125 gram per liter of sodium sperm oil alcohol sulfate and 0.125 gram per liter of Glaubers salt, and then rinsed again with water.

A washing test carried out for 3 hours gives the following values for surface shrinkage:

Percent surface shrinkage (a) Hypochlorite 38.86 ([2) Dichlorcyanuric acid 8.96 Untreated wool underwent a 48.17% surface shrinkage in the washing.

Example 5 2 samples of wool fabric are treated at a liquor ratio of 40:1 for an hour at 25 C. in two different baths (a and b) which, calculated on the weight of the fabric, contain 10% of sodium sulfate, 8% of sodium pyrophosphate and 4% of active chlorine in the form of hypochlorite (bath a) and dischlorcyanuric acid (bath b). The pH of the bath is adjusted to 7 prior to adding the wool.

The wool is removed from the oxidizing bath, rinsed for a short time with water, treated for an hour at 50 C. at a liquor ratio of 20:1 in a bath which contains 3 grams per liter of sodium dithionite, 0.125 gram per liter of sodium sperm oil alcohol sulfate and 0.125 gram per liter of Glaubers salt, and then rinsed again with water.

A washing test carried out for 2 hours gives the following values for surface shrinkage:

Percent surface shrinkage (a) Hypochlorite 18.35 (b) Dichlorcyanuric acid 9.96

Untreated wool underwent a 48.17% surface shrinkace in the washing. a

We claim:

1. In a process for feltproofing and shrinkproofing wool and wool-containing textiles the step which comprises treating said materials with an aqueous alkaline bath con tamlng an organic chloro oxidizing agent consisting of dichlorcyanuric acid.

In a process for feltproofing and shrinkproofing wool and wool-containing textiles the step which comprises treating said materials in an aqueous alkaline bath which contains a chloro Organic oxidizing agent consisting of dichlorcyanuric acid in an amount corresponding to about 2 to 5% by weight of active chlorine, based on the amount of textile material.

3. Aqueous treatment baths for feltproofing and shrinkproofing wool and wool-containing textiles which contain a chloro organic oxidizing agent consisting of dichlorcyanuric acid in an amount corresponding to a content of active chlorine of about 2 to 5% by weight and which have been adjusted to apH of about 7 to 8.5.

References Cited in the tile of this patent UNITED STATES PATENTS 2,185,210 MacMahon et al Ian. 2, 1940 2,429,082 Stevenson et a1 Oct. 14. 1947 2,457,033 Clapham et a1 Dec. 21, 1948 2,590,811 Zimmerman et a1 Mar. 25, 1952 2,671,006 McLauchlan Mar. 2, 19 4 2,702,737 Koons et al Feb. 22, 1955 2,739,034 Fell Mar. 20, 1956 UNITED STATES PATENT OFFICE QEHHQATE 0F CRRECTIGN Patent Nos 3 O7l 431 January 1 1963 Heinrich Mertens et alu It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1 line 23 for "was" read with column 4. has .29 for "dis 5hlorcyanu:rie read me dichlorcyanurie Signed and sealed this 1st day of October 1963:,

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Commissioner of Patents Attesting Officer 

2. IN A PROCESS FOR FELTPROOFING AND SHRINKPROOFING WOOL AND WOOL-CONTAINING TEXTILES THE STEP WHICH COMPRISES TREATING SAID MATERIALS IN AN AQUEOUS ALKALINE BATH WHICH CONTAINS A CHLORO ORGANIC OXIDIZING AGENT CONSISTING OF DICHLORCYANURIC ACID IN AN AMOUNT CORRESPONDING TO ABOUT 2 TO 5% BY WEIGHT OF ACTIVE CHLORINE, BASED ON THE AMOUNT OF TEXTILE MATERIAL. 